content: /**
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
   * compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License is
   * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See
   * the License for the specific language governing permissions and limitations under the License.
   */
  
  package io.reactivex.observable.internal.operators;
  
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicBoolean;
  
  import io.reactivex.common.*;
  import io.reactivex.common.internal.disposables.DisposableHelper;
  import io.reactivex.observable.*;
  import io.reactivex.observable.internal.queues.SpscLinkedArrayQueue;
  
  public final class ObservableTakeLastTimed<T> extends AbstractObservableWithUpstream<T, T> {
      final long count;
      final long time;
      final TimeUnit unit;
      final Scheduler scheduler;
      final int bufferSize;
      final boolean delayError;
  
      public ObservableTakeLastTimed(ObservableSource<T> source,
              long count, long time, TimeUnit unit, Scheduler scheduler, int bufferSize, boolean delayError) {
          super(source);
          this.count = count;
          this.time = time;
          this.unit = unit;
          this.scheduler = scheduler;
          this.bufferSize = bufferSize;
          this.delayError = delayError;
      }
  
      @Override
      public void subscribeActual(Observer<? super T> t) {
          source.subscribe(new TakeLastTimedObserver<T>(t, count, time, unit, scheduler, bufferSize, delayError));
      }
  
      static final class TakeLastTimedObserver<T>
      extends AtomicBoolean implements Observer<T>, Disposable {
  
          private static final long serialVersionUID = -5677354903406201275L;
          final Observer<? super T> actual;
          final long count;
          final long time;
          final TimeUnit unit;
          final Scheduler scheduler;
          final SpscLinkedArrayQueue<Object> queue;
          final boolean delayError;
  
          Disposable d;
  
          volatile boolean cancelled;
  
          Throwable error;
  
          TakeLastTimedObserver(Observer<? super T> actual, long count, long time, TimeUnit unit, Scheduler scheduler, int bufferSize, boolean delayError) {
              this.actual = actual;
              this.count = count;
              this.time = time;
              this.unit = unit;
              this.scheduler = scheduler;
              this.queue = new SpscLinkedArrayQueue<Object>(bufferSize);
              this.delayError = delayError;
          }
  
          @Override
          public void onSubscribe(Disposable d) {
              if (DisposableHelper.validate(this.d, d)) {
                  this.d = d;
                  actual.onSubscribe(this);
              }
          }
  
          @Override
          public void onNext(T t) {
              final SpscLinkedArrayQueue<Object> q = queue;
  
              long now = scheduler.now(unit);
              long time = this.time;
              long c = count;
              boolean unbounded = c == Long.MAX_VALUE;
  
              q.offer(now, t);
  
              while (!q.isEmpty()) {
                  long ts = (Long)q.peek();
                  if (ts <= now - time || (!unbounded && (q.size() >> 1) > c)) {
                      q.poll();
                      q.poll();
                  } else {
                      break;
                  }
              }
          }
  
          @Override
          public void onError(Throwable t) {
              error = t;
              drain();
          }
  
          @Override
          public void onComplete() {
              drain();
          }
  
          @Override
          public void dispose() {
              if (!cancelled) {
                  cancelled = true;
                  d.dispose();
  
                  if (compareAndSet(false, true)) {
                      queue.clear();
                  }
              }
          }
  
          @Override
          public boolean isDisposed() {
              return cancelled;
          }
  
          void drain() {
              if (!compareAndSet(false, true)) {
                  return;
              }
  
              final Observer<? super T> a = actual;
              final SpscLinkedArrayQueue<Object> q = queue;
              final boolean delayError = this.delayError;
  
              for (;;) {
                  if (cancelled) {
                      q.clear();
                      return;
                  }
  
                  if (!delayError) {
                      Throwable ex = error;
                      if (ex != null) {
                          q.clear();
                          a.onError(ex);
                          return;
                      }
                  }
  
                  Object ts = q.poll(); // the timestamp long
                  boolean empty = ts == null;
  
                  if (empty) {
                      Throwable ex = error;
                      if (ex != null) {
                          a.onError(ex);
                      } else {
                          a.onComplete();
                      }
                      return;
                  }
  
                  @SuppressWarnings("unchecked")
                  T o = (T)q.poll();
  
                  if ((Long)ts < scheduler.now(unit) - time) {
                      continue;
                  }
  
                  a.onNext(o);
              }
          }
      }
  }
  